1. Field of the Invention
This invention relates to the power train of an automotive vehicle for transmitting power from the engine to the driving wheels, particularly to that part of the power train known as the speed change transmission, and more particularly to speed change transmissions capable of receiving power from more than one power source.
2. Description of the Prior Art
The rising cost of automotive fuel has created a need for means for improving the fuel efficiency of automotive vehicles. Various solutions have been proposed.
One solution has been the hybrid automobile which uses an electric motor powered by batteries together with an internal combustion engine. It uses both the engine and the electric motor to provide sufficient combined power to accelerate and climb, etc., and then uses either the engine or the electric motor to travel economically at cruising speeds. The engine generally provides the power for recharging the batteries, so that in reality substantially all the power is provided by the automotive fuel.
Such hybrid systems are of high cost and complexity. The batteries can cost up to $5000.00 per vehicle, and have a limited service life of approximately 80,000 miles. The electric motor, electric generator and the necessary power transmission and control system as well as the means for integrating their function with that of the internal combustion engine result in additional high manufacturing and maintenance costs.
Another proposed approach for improving fuel economy is the use of two or more engines in one vehicle. All the engines are operated to produce enough power for acceleration, climbing, etc., and only one engine is used to maintain cruising speed for economical long distance travel.
U.S. Pat. No. 6,179,078 to Belloso discloses a fuel efficient and inexpensive automobile having two engines coupled to drive wheels by way of a continuously variable ratio torque converter. The vehicle uses both engines for quick acceleration, then uses either engine for economical cruising. A disadvantage of this system is the limited power capacity and limited speed range of current continuously variable ratio torque converters.
U.S. Pat. No. 6,637,283 to Belloso discloses a Control Apparatus for a Continuously Variable Transmission for extending the drive ratios and versatility of the CVT. It increases its operational speed range, provides reverse functionality and has the capacity to accommodate two different power sources. Its disadvantage is that most currently available continuously variable transmissions, particularly those using variable-pitch pulleys, have only limited power handling capacity, especially when compared to the standard manual and automatic transmissions that are in general use in automotive vehicles today. This control apparatus is not readily adaptable for use in these standard manual and automatic transmissions.
U.S. Pat. No. 4,439,989 to Yamakawa discloses a system with at least two engine units, a primary engine unit and an auxiliary engine unit, each coupled to a transmission through an electromagnetic power clutch. It is equipped with means for operating the two engines in a proper phase difference of, preferably, 180 degrees to prevent unwanted vibrations. A problem with this engine is the high complexity of the system used to make the engine units run at the specified proper phase difference between the engine units. Another disadvantage is that it does not readily lend itself to the use of dissimilar engine units, particularly units that differ in their optimal operating speeds. Furthermore this patent does not teach any improvement or modification of the standard manual or automatic transmissions to facilitate fuel savings.
Although improved fuel efficiency can be achieved through the use of a smaller fuel-efficient engine in an automobile, particularly for maintaining cruising speed, additional power is required for acceleration and hill climbing. Modified engine systems of the prior art have not proved truly satisfactory, either because of their excessive cost and complexity, or because of reliance upon continuously variable torque converters having inadequate power handling capacity.
There is, therefore, a need for an engine system which will not only permit selective use of power from a plurality of engines but will also make use of currently available standard manual or automatic transmissions, and take advantage of their proven versatility, reliability, durability and power-handling capacity.
It is accordingly a primary purpose of this invention to provide an automotive transmission equipped with multiple input ports for receiving power from a plurality of power sources and further equipped with means for selectively transmitting power from said sources to a common output shaft for eventual transmission to the driving wheels.
It is a particular object of this invention to provide an automatic transmission equipped with multiple input ports and adapted to receive power from multiple internal combustion engines.
It is also an object of this invention to provide a manual transmission equipped with multiple input ports for receiving power from multiple engines.
It is a further purpose of this invention to provide a transmission capable of receiving power from multiple power sources of dissimilar types, dissimilar operating speeds and dissimilar power output.
It is a further purpose of this invention to provide a fuel-efficient automotive vehicle equipped with two or more internal combustion engines, said vehicle being capable of selectively using the combined power of a plurality of said engines for acceleration, climbing, etc., and capable of selectively using power from a lesser number of said engines for economical travel.
It is yet another object of this invention to provide an automotive vehicle of the aforesaid nature that employs the currently generally used types of automatic or manual transmissions with a minimum of modifications of said transmissions.
It is a still further object of this invention to provide an automotive vehicle of the aforesaid nature wherein the additional power from the second (and third, etc.) engine/power source will be automatically engaged and disengaged, as needed, without requiring the operator to make substantial changes in the manner in which he regularly operates an automotive vehicle, hence without requiring him to have to upgrade his skill as an operator of motor vehicles.
These objects and other objects and advantages of the invention will be apparent from the following description.